Compressor



A ,,1936.- .J. c. DURYEE I 2,036,799

COMPRESSOR Filed June 19, 1935 IHVE'h'bOT Jerome Dugee,

ctcwneg.

' l utented Apr, l ldd d ihhdttlldtl mnusa llerome lhuryee, llort llll'ayne, hid, assignor to General Electric ificmpany, a corporation at New llerh 'Plppllcatlon dune it'll, ltthderlal lilo, twat e coma; lei. litt ttll ltly invention relates to compressors and more particularly to an arrangement for the noise resulting iron: the operation of the Ell . when the reed type discharge valve strilres its all discharge valve thereof.

tlompressors oi the reciprocating type are ordinarily provided with a discharge valve which operates automatically in response to the differential fluid pressure existing between the interior of the compressor cylinder and chamher in which the compressed fluid is discharged. Discharge valves or the reed type are frequently employed in compressorsutilized in reiriger ating systems, and the lilre, and although these valves have a number of desirable characteristics, they are frequently the source oi noise during the operation or the compressor. l have found that one serious source ot noise incident to the operation or the discharge valves of the reed type is the sound waves set up in the elastic fluid within the compressor cylinder seat upon closing. This is probably due in part to the fact that the reed type valve has an inherent tendency to vihrate when struclr a blow, as upon seating, because of its extremely resilient construction. The noise is also due in part to the fact that a reed type valve depends to a greater extent upon pressure for its closing operation, thandoes a, spring loaded valve, for

example, and as a consequencethe piston in the compressor cylinder has already begun its suc tion stroke before the reed type discharge valve closes. This means that a chamber oi comparatively large volume is available above the piston upon closing of the reed type valve in which sound Waves may reverberate. The closing of the reed type valve causes a dull thudding sound which reverberates in the cylinder whereas a spring operated valve seats more;

quickly and usually the only noise heard is the click of the valve on the seat. The noise incl-.

dent to the closing or the discharge valve appears to bear a direct relation to'the volume or fluid between the discharge valve and header the compressor piston isprevented in order that ol the valve such a cohunn by the closing element.

, 'l urther objects and advantages or my invention will become apparent'as the i'ollowingde scription proceeds and the features of novelty which characterized my invention will he pointed out with particularity in the claims an-= netted to and iorminga part or this specification.

and idle, lit is an exploded perspective view of the parts or one or the inlet valve assemblies of the compressor shown in the, l.

Referring to the drawing, 1 have shown in Fig. l the upperportion of a two cyllnder re ciprocatlng type. refrigerant compressor pro vided with a cylinder casing it having two vertical cylindrical cylinder bores ll and-i2 there.

in. The cylinder casing 7 it is provided with integral cooling fins it extending from the side walls thereof which aid in dissipating heat from the cylin er walls to the surrounding air. Pie:- tcns lie and the are reciprocated in the cylinder bores ill and it, respectively, lay an. electric motor or'other suitable. driving arrangement.

The upper ends or the cylinder bores it and it are closed by a valve plate it which extends entirely across the top of the cylinder casing ill and the vertical sides of, which are in alignment vsnith the adjacent portion of the vertical walls or the cylinder casing lll. Vertical cylindrical discharge passages it extend through the valve plate i l and communicate with the cylinder here it. The valve plate it is also provided with a similar pair of cylindrical discharge passages it extending therethrough which communicate with the cylinder hore lt. The pairs or discharge passages it and it are surrounded by annular inlet passages lland lll respectively. A horizontal passage is formed in the valve plate it connects the inlet passages ill and it in series and an intake passage tt formed in the valve plate it communicates with theannular inlet passage id 'The provision or a compressor valve plate having a discharge passage therein and an annulll lar inlet passage surrounding the same is not my invention but is the invention of Clark Orr, and is described and claimed in his copending reverberating sound waves may not be set up in n application Serial No. 27,351, filed June 19 1935, M

central portions of .the valve retainers 23 and 33- 65 and assigned to the General Electric Company, assignee of my. present invention.

I have provided an arrangement which forms a tortuous passage between the heads of the pistons II a and I2a in the cylinder bores II and I2 and the pairs of discharge passages I5 and I6 respectively. As a result, even though the discharge passages I5 and I6 are in communication with the cylinder bores II and I2 respectively, the elastic fluid in the tortuous communicating passage will conduct sound very poorly as compared to a rectilinear column of elastic fluid and the noise resulting from the operation of the discharge valve which closes the pairs of discharge passages I5 and I6 is minimized. In the particular arrangement illustrated in the drawing, the inlet valve structure is designed to prevent the formation of a rectilinear column of elastic fluid between the discharge valve and the head of the adjacent compressor piston in which sound waves might otherwise reverberate. The lower sides of the inlet passages I I and I 8 are closed by flat annular inlet valve elements 2| and 22, respectively, which are seated on flat machined surfaces formed on the valve plate I4 about the inner and outer peripheries of the lower ends of the inlet passages I1 and it. The inlet valve elements 2| and 22 are supported on inlet valve springs 23 and 24 respectively which bias them to the closed position. The valve spring 23, for example, includes an annular base portionand an integral inner C-shaped spring portion 23a. The springs 23 and 24 are identical and may be stamped from sheets of spring steel or the like and the C-shaped portion thereof bent upwardly in the position illustrated in Fig. 2. The top 25 of the C-shaped portion 23a of the spring 23, for example, is preferably flattened in order to facilitate the support of theflat annular inlet valve element 2| thereon, the spring 24 being similarly formed. Lateral displacement of the valve elements 2| and 22 is prevented by annular spacers 2'6 and '21 of the same form having internally projecting stops 23 formed thereon which engage the sides of the inlet valve elements 2| and 22 thus preventing lateral movement thereof. The springs 2| and 22 and spacers 26 and 21 are supported on disk-shaped valve retainers 29 and 30. The valve springs 2| and 22, the spacers 26 and 21, and valve retainers 29 and 30 are held in position by machine screws 3| and 3Ia which pass through registering holes formed therein and engage tapped holes 32 and 32a formed in the lower surface of thevalve plate I4. The valve retainers 23 and 30 are provided with a series ofslots 33 and 34 therein,

respectively, which afford communication between the inlet and discharge passagesin the valve plate .and the interior of the cylinder bores II and I2. The slots 33 and 34 are preferably arranged on the arcs of concentric circles and are disposed at the sides of the pairs of discharge passages I5 and I6, respectively, so that the solid are presented to the lower ends ofthe pairs of discharge passages I5 and I6. As a consequence, fluid passing from the interior of the cylinder bores II and I2 to the discharge es I5 and I6 respectively must follow a tortuous path and the formation of a rectilinear column of elastic fluid between the discharge valve at the end of the discharge passages and the heads of the pistons Na and I20 is prevented.

The counterbored upper ends of the pairs of discharge es I! and I6 are alternately opened and closed by a reed type discharge valve. The reed type discharge valve illustrated includes a flat rectangular discharge valve element 35 made of a thin piece of flexible spring steel or the like, the valve element is pushed downwardly against the flat upper surface of the valve plate I4 by a. series of flat rectangular steel leaf springs 36, the lower one of which has flattened outer ends 31 and' 38 which bear against the adjacent end portions of the valve element 35. The springs 36 and valve element 35 are secured to the top of the valve plate I4 by a screw 39 which passes through centrally located holes formed therein and is threaded in a tapped hole formed in the top of the valve plate I4. A washer 40 separatesthe group of springs 36 and the valve element 35 and a spacing block 4| is pressed between the head of the screw 39 and the upper side of the springs 36. When the pressure of the fluid within the discharge passages I5 or I6, for example, reaches a predetermined value, the portion of the discharge valve element 35 above the ends of the passages |5 or I6 is flexed or bowed upwardly into an arcuate configuration spanning the top of the discharge passages in spaced relation thereto thus permitting the escape of compressed fluid therefrom.

The top of the. valve plate I4 is covered by a cylinder head block 42 which is provided with a recess 43 in the lower face thereof entirely'surrounding the upper ends of the pairs of discharge passages I5 and I6 and the reed type discharge valve mechanism therefor. The recess 43 communicates with a horizontal discharge passage 44 formed in the cylinder head block 42. An integral annular flange 45 is provided on the side of the cylinder head block 42 surrounding the end of the passage 44. The flange 45 is provided with tapped holes 46 and 41 to which a suitable pipe fitting, or the like, attached to a discharge conduit may be secured. An intake passage 48 is provided at the side of the cover block 42 opposite the passage 44, the passage 43 communicating at one end with the intake passage 20 formed in the valve plate I4. It will be seen that the passage 48 does not communicate with the recess 43 formed in the cover block 42, however. An integral annular flange 43 surrounds the outer end of the passage 46 the flange 43 being provided with tapped holes III and 5| to which a suitable pipe fitting, or the like, attached to an intake conduit may be ured. A gasket 52 is provided between the adjacent surfaces of the cylinder casing I0 and the valve plate I4 in order to prevent the leakage of compressed fluid therefrom. A gasket 53 is also'provided between the adjacent surfaces of the valve plate I4 and the cylinder head block 42 in order to prevent the leakage of compressed fluid therebetween. The cylinder head block 42 and valve plate I4 are held in their assembled position on the cylinder casing I0 by suitable bolts or the like. (not shown).

In the operation of the machine described above, the pistons Ila and I 2a are reciprocated the passage it and flows by gravity through the passage lit to the crank case or other lubricant reservoir. When the piston lla,.for example, moves downwardly on its suction strolre the fluid pressure on the lower side of the inlet valve element it is decreased. When the pressure oithe gaseous refrigerant in the inlet passage it exceeds the pressure of the gaseous refrigerant in the cylinder bore lit. by a predetermined amount, the inlet valve element ll and its supporting spring it are lorced downwardly, thus establishing communication between the inlet passage ill and cylinder here it. Gaseous refrigerant then enters the cylinder bore ill passing thereto through the slots and lit formed in the valve retainer The portion of the discharge valve element extending across the outer ends of the discharge passage it remains hat, thus maintaining the discharge passages it closed, during the suction strolre ot the piston lilo since the pressure in the recess it exceeds the pressure in the cylinder bore it during the suction strobe. When the piston lla again moves upwardly on the compression strolre, the gaseous relrigerant in the cylinder here it is compressed and the inlet valve element t? moved upwardly closing the passage l8 due to the increase in pressure in the cylinder bore it with respect to the pressure in the inlet passage When the pressure in the cylinder bore it exceeds the pressure in the recess by a predetermined amount, depending upon the stiffness or the discharge valve element the latter is flexed upwardly thus opening the discharge passages iii and allowing the escape oi compressed gaseous refrigerant from the cylinder here it into the discharge recess its the piston ltd again nd oves downwardly on its next suction strolre, the discharge valve element flexes back to the flat closed position illustrated in the drawing when the pressure in the recess exceeds the pressure in the cylinder here by a predetermined amount. There is a small time lag in the movement of the reed type discharge valve element so that the piston lilo has moved downwardly; thus forming a charn= her or substantial volume in the cylinder bore it, before the discharge valve element has completed its closing movement. Since the apertures i l in the inlet valve retainer are" laterally displaced with respect to the lower.

ends of the discharge passages lit, howeven'tloe formation of a rectilinear colurrm oi? elastic fluid between the discharge valve element th and the head of the piston lid is prevented. As a consequence, reverberatlons incident to the closing of the discharge valve element it are minimized even though the piston Illa has moved downwardly a sufficient amount to form a chamber of fairly large volume thereabove. The

pistons lid and its are suitably connected to a crank shaft, or other driving arrangement therefor, in such manner that the piston lilo moves through its compression stroke at the time the piston its is moving through its suction stroke and vice versa. Thus, except for the difference in relative time of operation, gas-- eous refrigerant is compressed in the cylinder bore it and discharged therefrom in the same manner as described above with respect to the cylinder bore it.

While I have shown a particular embodiment of my inventiongin connection with a compression type refrigerating machinel do not desire my invention to be limited to. the particular I taro lll construction shown and described and I intend in the appended claims, to cover all modifica- Fons within the spirit and scope of my invenion.

What l. claim as new and desire to secure by Letters Patent in the United States is:

l. A compressor for elastic fluid comprising in combination a compression cylinder having a longitudinal cylinder bore therein, a reciprocating piston in said cylinder bore, said cylinder having a discharge passage formed in one wall 'thereoi, a discharge valve element of the reed type tor closing said discharge passage, and means for preventing the flow of elastic fluid in a rectilinear column between said piston and said discharge valve element in which reverberating sound waves may be set up by the closing oi said valve element.

2. A compressor for elastic fluid comprising in combination a compressor cylinder having a longitudinal cylinder bore therein, a reciprocating piston in said cylinder bore, a valve plate closing one end of said cylinder here, said valve plate having a d'mcharge passage formed therein, a discharge valve element of the reed type mounted on the errterior side of said valve plate for closing said discharge passage, and means for preventing the flow or elastic iiuid in a rectilinear column between said piston and said discharge element in which reverberating sound waves may be set up by the closing oi said valve element. 7

A compressor for elastic fluid comprising in combination a compression cylinder having a longitudinal cylinder bore therein, a reciprocating piston in said cylinder bore, said cylinder having a discharge passage formed in one wall thereof, a discharge valve element of the reed type for closing said discharge passage, and means forming a tortuous passage between said discharge valve element and said piston for minimiaing the reverberating sound waves set passage formed in one wall thereof, a discharge valve element of the reed type for closing said discharge passage, an inlet valve assembly for closing said inlet passage said inlet valve assembly including an aperturecl valve retainer, said valve retainer forming a tortuous passage between said discharge valve element and said piston for minimining the reverberatihg sound waves set up by the closing oi said valve element.

5 A compressor for elastic fluid comprising in. combination a compression cylinder having a longitudinal cylinder bore therein, a reciprocating piston in said cylinder bore, a valve plate closing one end of said cylinder bore said valve plate having a discharge passage and an inlet passage formed therein, a discharge valve ele ment of the reed type mounted on the exterior side of said valve plate for closing said discharge passage, an inlet valve assembly for closing said inlet passage said inlet valve assembly including an apertured inlet valve retainer, said inlet valve retainer forming a tortuous passage between said discharge valve element and said piston for minimizing reverberating sound waves set up by the closing of said discharge valve element.

6. .llcompressor for elastic fluid comprising in combination a compression cylinder having a longitudinal cylinder bore therein, a reciprocating piston in said cylinder bore, a valve plate closing one end of said cylinder bore, said valve plate having discharge and inlet passages formed therein, said inlet passage being annular in shape and surrounding said discharge passage, a discharge valve element of the reed type mounted on the exterior side of said valve plate for closing 10 said discharge passage, an annular inlet valve element for closing said inlet passage, and means including a disk-shaped valve retainer for supporting said inlet valve element adjacent the inner end of said inlet passage, said valve retainer being provided with a series of apertures laterally displaced from the inner end of said discharge passage for minimizing reverberating sound waves set up by the closing 01 said discharge valve element. 4

JEROME C. DURYEE. 

